文档的最大大小为2 MB，无法增加.在您的情况下，您可以将图像存储在Blob存储中，并将url作为属性附加到要保存的文档中，这将节省几个字节.

The maximum size of a document is 2 MB and cannot be increased. In your case you can store the image in blob storage and attach the url as a property to the document you are saving which will save few bytes.